Thanks as always for your input gentlemen.
Brian, there is definatley not a drought, although it has dried up and gotten hot recently. As far as a dearth, there is nothing obviously in bloom at the moment except for clover, but there should be plenty of that in the neighborhood. The bees from both hives are still coming and going as normal, although I have noticed that there is less pollen ocming in than there was perviously.
The bees moved 20+ 'mummies' out of the hive several days ago, and there were not all that many in the first place, so I am not worried about them cleaning it up, whatever the cause.
During the inspection I did not see any fuzz anywhere, but I did not check under any cappings. If I still see evidence of a problem next time I inspect, I will open some up and see. If it spreads I will consider requeening, but for now I will leave them alone.
From the reading I have done, aside from the 'fuzz' stage, it still sounds like chalkbrood to me, but I have not found any difinitive descriptions of the symptoms of chillbrood. (Or even a single commonly used term: chillbrood, chilled brood, broodchill, etc.) What I saw in my hive looks exactly like photos of the 'mummy' stage of chalkbrood.
After I thought about it some more, I thoutht of something else that may have contributed to this aside from the dampness and lack of sunlight: This was the hive that would not work the 2 leftmost frames, and was tending to build vertically rather than horizontly. It was suggested that I move the whole brood nest to the left and put those 2 frames on the right side. I did so several weeks ago. (I inspect roughly every 8 to 14 days, but neglected my notes earlier this summer.) The mummies were found only near the top-back of the (current) second and third frames. Since these frames used to be closer to the center, (4 and 5) I wonder if the nurse bees were just not working that part of the hive as well. Could this lead to chillbrood or chalkbrood in a localized area?
Next time I will just let them do their own thing. Oh, and make sure that I take better notes.